The present invention relates to the treatment of hemorrhoids by elastic band ligation. More specifically the invention relates to an elastic band ligation device that is provided with a locking mechanism which prevents premature elastic band deployment.
Commonly assigned patent applications entitled ELASTIC BAND LIGATION DEVICE WITH ITEGRATED OBTURATOR AND METHOD FOR TREATMENT OF HEMORRHOIDS (U.S. application Ser. No. 13/972,144) and ELASTIC BAND LIGATION DEVICE WITH ANTI-PINCH FEATURE AND METHOD FOR TREATMENT OF HEMORRHOIDS (U.S. application Ser. No. 13/972,202) are filed simultaneously herewith, the entire disclosures of which are hereby incorporated by reference herewith.
Treatment of hemorrhoids by elastic band ligation typically involves placing an elastic band on hemorrhoidal tissue in the rectum well above the “dentate line” (the junction of the sensitive squamous epithelium known as the “anoderm” and the insensitive lining of the rectum known as the “mucosa”), where there is little sensation. The tissue trapped in the band is cut off from its blood supply, degenerates and is sloughed, and the elastic band along with the sloughed tissue is passed with bowel motions. More importantly, however, the resulting healing process causes the tissue in the vicinity to become fixed, and prolapse of the hemorrhoidal tissue is minimized. This fixation of the tissue serves to eliminate the hemorrhoidal symptoms.
Many devices exist on the market utilizing the elastic band ligation technique. Examples are U.S. Pat. No. 5,203,863 to Bidoia, U.S. Pat. No. 5,122,149 to Broome, U.S. Pat. No. 5,158,563 to Cosman and U.S. Pat. No. 5,741,273 to O'Regan. The devices disclosed in U.S. Pat. No. 5,203,863 to Bidoia, U.S. Pat. No. 5,122,149 to Broome, U.S. Pat. No. 5,158,563 to Cosman are generally designed to be used in conjunction with an instrument such as a proctoscope or anoscope to directly see the area to be banded. In some cases, it is necessary to employ an assistant to hold the proctoscope or anoscope. However, the use of these scopes, which are generally larger in diameter than banding apparatus, can cause considerable discomfort to a patient and more specifically to one who is suffering symptoms of hemorrhoids and other associated issues.
The device disclosed in U.S. Pat. No. 5,741,273 to O'Regan relates to an elastic band ligation device for treatment of hemorrhoids that may be used without directly seeing the site for banding. Thus, it may be used without a proctoscope or anoscope or any other type of scope or viewing technique. Therefore, because the device can be inserted into the rectum and positioned appropriately without simultaneous visualization, or the need for any type of scope, the banding procedure performed in this manner causes less discomfort to the patient. This technique also allows for a more proximal placement of the elastic band, which increases the technique's efficacy as well as causing less discomfort and fewer complications. This device has a suction device incorporated therein to draw hemorrhoidal tissue into an aperture for banding without requiring a second operator or connection to an aspirator.
Ligation is typically performed by initially inspecting the site through a small scope such as a sigmoidoscope, anoscope, proctoscope or other type of scope and making a mental note as to the area where the band should optimally be placed. The scope is then removed and the ligation device is placed in the rectum. This is known as the “Blind” or “Touch” technique.
An alternative application is to visualize the area with an anoscope and insert the banding through the lumen of the anoscope and band directly. This can be done if the operator prefers a direct visual approach. This is known as the “Trans-anoscopic” or “visual” technique.
The front end of the device is inserted well past the site for banding. Then, the device is gently withdrawn while it is pointed in the direction of the anal canal, minimizing patient discomfort. As the device is being withdrawn, a palpable “ridge” on the outside of the outer tubular member is noted at the anal verge which can be used as a guide to the level where the band should optimally be placed in the rectum. The device is then gently angled or “aimed” toward the hemorrhoid to be treated. In larger patients, the operator may choose to place the device 1-2 cm further in through the anus prior to “aiming” the device towards the hemorrhoid to be treated.
However, it has been found that prior devices suffer from the drawback that the elastic band(s) may undergo premature deployment, with the result that it is necessary to withdraw the device, recover the deployed elastic band within the rectum and begin the procedure again. This gives rise to delays and additional discomfort to the patient. From a patient and physician perspective, a quick smooth banding is most desirable. One situation that can prolong the treatment process is if the band is deployed at the incorrect moment, leading to the need to re-load the band on the device. If this occurs when the device is inserted in the patient, the discomfort to the patient is increased.
Currently the main cause for pre-mature band deployment is that the pusher (that pushes the band off the body of the ligator) can move freely on its own as it is held with minimal frictional force on the device. If the pusher moves for whatever reason, the band can be deployed at the incorrect moment. A need exists therefore for a mechanism that would give the physician control over timing as to when the band is deployed. The general function of the device would remain the same, thereby permitting training for existing users to be relatively quick. The present invention seeks to satisfy that need.